Bug 858101 - Followup fix for the lack of Cu.isXrayWrapper on esr17/b2g18. r=me, a=bustage

dom/tests/browser/browser_ConsoleAPITests.js

@@ -6,6 +6,9 @@
 const TEST_URI = "http://example.com/browser/dom/tests/browser/test-console-api.html";
 
 var gWindow, gLevel, gArgs, gTestDriver;
+function isXrayWrapper(x) {
+  return x && typeof x == 'object' && XPCNativeWrapper.unwrap(x) != x;
+}
 
 function test() {
   waitForExplicitFinish();
@@ -52,7 +55,7 @@ function testConsoleData(aMessageObject) {
       // It'd be nice to just use XPCNativeWrapper.unwrap here, but there are
       // a number of dumb reasons we can't. See bug 868675.
       var arg = aMessageObject.arguments[i];
-      if (Components.utils.isXrayWrapper(arg))
+      if (isXrayWrapper(arg))
         arg = arg.wrappedJSObject;
       is(arg, a, "correct arg " + i);
     });